1
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Bottoni P, Gionta G, Scatena R. Remarks on Mitochondrial Myopathies. Int J Mol Sci 2022; 24:ijms24010124. [PMID: 36613565 PMCID: PMC9820309 DOI: 10.3390/ijms24010124] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/15/2022] [Accepted: 12/17/2022] [Indexed: 12/24/2022] Open
Abstract
Mitochondrial myopathies represent a heterogeneous group of diseases caused mainly by genetic mutations to proteins that are related to mitochondrial oxidative metabolism. Meanwhile, a similar etiopathogenetic mechanism (i.e., a deranged oxidative phosphorylation and a dramatic reduction of ATP synthesis) reveals that the evolution of these myopathies show significant differences. However, some physiological and pathophysiological aspects of mitochondria often reveal other potential molecular mechanisms that could have a significant pathogenetic role in the clinical evolution of these disorders, such as: i. a deranged ROS production both in term of signaling and in terms of damaging molecules; ii. the severe modifications of nicotinamide adenine dinucleotide (NAD)+/NADH, pyruvate/lactate, and α-ketoglutarate (α-KG)/2- hydroxyglutarate (2-HG) ratios. A better definition of the molecular mechanisms at the basis of their pathogenesis could improve not only the clinical approach in terms of diagnosis, prognosis, and therapy of these myopathies but also deepen the knowledge of mitochondrial medicine in general.
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Affiliation(s)
- Patrizia Bottoni
- Dipartimento di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Giulia Gionta
- Dipartimento Scienze Anatomiche Istologiche Medico Legali e dell’Apparato Locomotore—Sezione di Anatomia Umana, Università La Sapienza di Roma, Via Alfonso Borelli 50, 00161 Rome, Italy
| | - Roberto Scatena
- Dipartimento di Medicina di Laboratorio, Madre Giuseppina Vannini Hospital, Via di Acqua Bullicante 4, 00177 Rome, Italy
- Correspondence:
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2
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Finsterer J. Atheromatosis of the Scalp: A Novel Feature of Chronic Progressive External Ophthalmoplegia Plus Due to a Single Mitochondrial DNA Deletion. Cureus 2021; 13:e20641. [PMID: 35103203 PMCID: PMC8783651 DOI: 10.7759/cureus.20641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2021] [Indexed: 11/23/2022] Open
Abstract
Chronic progressive external ophthalmoplegia (CPEO) manifests phenotypically as ptosis with ophthalmoplegia or CPEO-plus, with the affection of muscles or organs other than the extra-ocular eye muscles. Herein, a case of CPEO-plus caused by a single mitochondrial DNA (mtDNA) deletion is represented, along with several previously unreported phenotypic features. The patient is a 76-year-old Caucasian female who had experienced slowly progressive bilateral ptosis since the age of 15, followed by gradual ophthalmoparesis without double vision. Since the age of 56, she had developed mild quadriparesis, depression, easy fatigability, hypersomnia, a facial tic, optic atrophy, cataract, glaucoma, hepatomegaly, hepatic steatosis, cholecystolithiasis, diverticulosis, hyperhidrosis, mild hyper-creatine-kinase-emia, hyperlipidemia, and hyperuricemia. Moreover, she had faced previously unreported manifestations of mitochondrial disorders, psoriasis, and multiple scalp atheromas. The phenotype and a single 5kb mtDNA deletion were employed to diagnose CPEO-plus. This case demonstrates that the phenotypic spectrum of CPEO-plus is broader than expected, that psoriasis and scalp atheromas are unique features of a mitochondrial disorder, and that CPEO progresses to CPEO-plus during the years.
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3
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Zhou X, Mikaeloff F, Curbo S, Zhao Q, Kuiper R, Végvári Á, Neogi U, Karlsson A. Coordinated pyruvate kinase activity is crucial for metabolic adaptation and cell survival during mitochondrial dysfunction. Hum Mol Genet 2021; 30:2012-2026. [PMID: 34169315 PMCID: PMC8522632 DOI: 10.1093/hmg/ddab168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/26/2021] [Accepted: 06/17/2021] [Indexed: 12/21/2022] Open
Abstract
Deoxyguanosine kinase (DGUOK) deficiency causes mtDNA depletion and mitochondrial dysfunction. We reported long survival of DGUOK knockout (Dguok-/-) mice despite low (<5%) mtDNA content in liver tissue. However, the molecular mechanisms enabling the extended survival remain unknown. Using transcriptomics, proteomics and metabolomics followed by in vitro assays, we aimed to identify the molecular pathways involved in the extended survival of the Dguok-/- mice. At the early stage, the serine synthesis and folate cycle were activated but declined later. Increased activity of the mitochondrial citric acid cycle (TCA cycle) and the urea cycle and degradation of branched chain amino acids were hallmarks of the extended lifespan in DGUOK deficiency. Furthermore, the increased synthesis of TCA cycle intermediates was supported by coordination of two pyruvate kinase genes, PKLR and PKM, indicating a central coordinating role of pyruvate kinases to support the long-term survival in mitochondrial dysfunction.
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Affiliation(s)
- Xiaoshan Zhou
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Stockholm 141 86, Sweden
| | - Flora Mikaeloff
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Stockholm 141 86, Sweden
| | - Sophie Curbo
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Stockholm 141 86, Sweden
| | - Qian Zhao
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Stockholm 141 86, Sweden
| | - Raoul Kuiper
- Division of Pathology, Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Stockholm 141 86, Sweden
| | - Ákos Végvári
- Division of Chemistry I, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm SE-171 65, Sweden
| | - Ujjwal Neogi
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Stockholm 141 86, Sweden
| | - Anna Karlsson
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Stockholm 141 86, Sweden
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4
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Bebbere D, Ulbrich SE, Giller K, Zakhartchenko V, Reichenbach HD, Reichenbach M, Verma PJ, Wolf E, Ledda S, Hiendleder S. Mitochondrial DNA Depletion in Granulosa Cell Derived Nuclear Transfer Tissues. Front Cell Dev Biol 2021; 9:664099. [PMID: 34124044 PMCID: PMC8194821 DOI: 10.3389/fcell.2021.664099] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/31/2021] [Indexed: 12/14/2022] Open
Abstract
Somatic cell nuclear transfer (SCNT) is a key technology with broad applications that range from production of cloned farm animals to derivation of patient-matched stem cells or production of humanized animal organs for xenotransplantation. However, effects of aberrant epigenetic reprogramming on gene expression compromise cell and organ phenotype, resulting in low success rate of SCNT. Standard SCNT procedures include enucleation of recipient oocytes before the nuclear donor cell is introduced. Enucleation removes not only the spindle apparatus and chromosomes of the oocyte but also the perinuclear, mitochondria rich, ooplasm. Here, we use a Bos taurus SCNT model with in vitro fertilized (IVF) and in vivo conceived controls to demonstrate a ∼50% reduction in mitochondrial DNA (mtDNA) in the liver and skeletal muscle, but not the brain, of SCNT fetuses at day 80 of gestation. In the muscle, we also observed significantly reduced transcript abundances of mtDNA-encoded subunits of the respiratory chain. Importantly, mtDNA content and mtDNA transcript abundances correlate with hepatomegaly and muscle hypertrophy of SCNT fetuses. Expression of selected nuclear-encoded genes pivotal for mtDNA replication was similar to controls, arguing against an indirect epigenetic nuclear reprogramming effect on mtDNA amount. We conclude that mtDNA depletion is a major signature of perturbations after SCNT. We further propose that mitochondrial perturbation in interaction with incomplete nuclear reprogramming drives abnormal epigenetic features and correlated phenotypes, a concept supported by previously reported effects of mtDNA depletion on the epigenome and the pleiotropic phenotypic effects of mtDNA depletion in humans. This provides a novel perspective on the reprogramming process and opens new avenues to improve SCNT protocols for healthy embryo and tissue development.
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Affiliation(s)
- Daniela Bebbere
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy.,Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Science, LMU Munich, Munich, Germany
| | - Susanne E Ulbrich
- ETH Zürich, Animal Physiology, Institute of Agricultural Sciences, Zurich, Switzerland
| | - Katrin Giller
- ETH Zürich, Animal Physiology, Institute of Agricultural Sciences, Zurich, Switzerland
| | - Valeri Zakhartchenko
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Science, LMU Munich, Munich, Germany
| | - Horst-Dieter Reichenbach
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Science, LMU Munich, Munich, Germany.,Bavarian State Research Center for Agriculture, Institute of Animal Breeding, Grub, Germany
| | - Myriam Reichenbach
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Science, LMU Munich, Munich, Germany.,Bayern-Genetik GmbH, Grub, Germany
| | - Paul J Verma
- Livestock Sciences, South Australian Research and Development Institute, Roseworthy, SA, Australia.,School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA, Australia
| | - Eckhard Wolf
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Science, LMU Munich, Munich, Germany
| | - Sergio Ledda
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy
| | - Stefan Hiendleder
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Science, LMU Munich, Munich, Germany.,School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA, Australia.,Davies Research Centre, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA, Australia.,Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia
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5
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Guo J, Duan L, He X, Li S, Wu Y, Xiang G, Bao F, Yang L, Shi H, Gao M, Zheng L, Hu H, Liu X. A Combined Model of Human iPSC-Derived Liver Organoids and Hepatocytes Reveals Ferroptosis in DGUOK Mutant mtDNA Depletion Syndrome. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2004680. [PMID: 34026460 PMCID: PMC8132052 DOI: 10.1002/advs.202004680] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/11/2021] [Indexed: 05/31/2023]
Abstract
Mitochondrial DNA depletion syndrome (MDS) is a group of severe inherited disorders caused by mutations in genes, such as deoxyribonucleoside kinase (DGUOK). A great majority of DGUOK mutant MDS patients develop iron overload progressing to severe liver failure. However, the pathological mechanisms connecting iron overload and hepatic damage remains uncovered. Here, two patients' skin fibroblasts are reprogrammed to induced pluripotent stem cells (iPSCs) and then corrected by CRISPR/Cas9. Patient-specific iPSCs and corrected iPSCs-derived high purity hepatocyte organoids (iHep-Orgs) and hepatocyte-like cells (iHep) are generated as cellular models for studying hepatic pathology. DGUOK mutant iHep and iHep-Orgs, but not control and corrected one, are more sensitive to iron overload-induced ferroptosis, which can be rescued by N-Acetylcysteine (NAC). Mechanically, this ferroptosis is a process mediated by nuclear receptor co-activator 4 (NCOA4)-dependent degradation of ferritin in lysosome and cellular labile iron release. This study reveals the underlying pathological mechanisms and the viable therapeutic strategies of this syndrome, and is the first pure iHep-Orgs model in hereditary liver diseases.
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Affiliation(s)
- Jingyi Guo
- University of Science and Technology of ChinaBioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory)Joint School of Life SciencesGuangzhou Institutes of Biomedicine and HealthChinese Academy of SciencesGuangzhou Medical UniversityHefei230026China
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Lifan Duan
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Xueying He
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Shengbiao Li
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Yi Wu
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Ge Xiang
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Feixiang Bao
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Liang Yang
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Hongyan Shi
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Mi Gao
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Lingjun Zheng
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
| | - Huili Hu
- The Key Laboratory of Experimental TeratologyMinistry of Education and Department of GeneticsSchool of Basic Medical SciencesShandong UniversityJinan250012China
| | - Xingguo Liu
- University of Science and Technology of ChinaBioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory)Joint School of Life SciencesGuangzhou Institutes of Biomedicine and HealthChinese Academy of SciencesGuangzhou Medical UniversityHefei230026China
- CAS Key Laboratory of Regenerative BiologyGuangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineInstitute for Stem Cell and RegenerationGuangzhou Institutes of Biomedicine and HealthUniversity of Chinese Academy of SciencesChinese Academy of SciencesGuangzhou510530China
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6
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Finsterer J. POLG1-related Mitochondrial Disorder with MNGIE- and Leigh-like Features. Ann Indian Acad Neurol 2020; 23:365-366. [PMID: 32606535 PMCID: PMC7313575 DOI: 10.4103/aian.aian_438_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/07/2019] [Accepted: 10/10/2019] [Indexed: 11/05/2022] Open
Affiliation(s)
- Josef Finsterer
- Krankenanstalt Rudolfstiftung, Messerli Institute, Vienna, Austria
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7
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Finsterer J. PRIMPOL variants cause multi-system mitochondrial disorder. Neurosci Res 2020; 160:S0168-0102(20)30393-X. [PMID: 32615141 DOI: 10.1016/j.neures.2020.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 06/16/2020] [Indexed: 10/24/2022]
Affiliation(s)
- Josef Finsterer
- Krankenanstalt Rudolfstiftung, Postfach 20, 1180 Vienna, Austria.
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8
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Wheeler JH, Young CKJ, Young MJ. Analysis of Human Mitochondrial DNA Content by Southern Blotting and Nonradioactive Probe Hybridization. CURRENT PROTOCOLS IN TOXICOLOGY 2019; 80:e75. [PMID: 30982231 PMCID: PMC6581606 DOI: 10.1002/cptx.75] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A single cell can contain several thousand copies of the mitochondrial DNA genome or mtDNA. Tools for assessing mtDNA content are necessary for clinical and toxicological research, as mtDNA depletion is linked to genetic disease and drug toxicity. For instance, mtDNA depletion syndromes are typically fatal childhood disorders that are characterized by severe declines in mtDNA content in affected tissues. Mitochondrial toxicity and mtDNA depletion have also been reported in human immunodeficiency virus-infected patients treated with certain nucleoside reverse transcriptase inhibitors. Further, cell culture studies have demonstrated that exposure to oxidative stress stimulates mtDNA degradation. Here we outline a Southern blot and nonradioactive digoxigenin-labeled probe hybridization method to estimate mtDNA content in human genomic DNA samples. © 2019 by John Wiley & Sons, Inc.
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Affiliation(s)
- Joel H. Wheeler
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901
| | - Carolyn K. J. Young
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901
| | - Matthew J. Young
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, Illinois 62901
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9
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Finsterer J. Valproate Is Contraindicated in POLG1 Mutations. Pediatr Gastroenterol Hepatol Nutr 2019; 22:105-106. [PMID: 30671381 PMCID: PMC6333585 DOI: 10.5223/pghn.2019.22.1.105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/28/2018] [Accepted: 04/06/2018] [Indexed: 11/19/2022] Open
Affiliation(s)
- Josef Finsterer
- Neurological department, Krankenanstalt Rudolfstiftung, Vienna, Austria
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10
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Poulton J, Finsterer J, Yu-Wai-Man P. Genetic Counselling for Maternally Inherited Mitochondrial Disorders. Mol Diagn Ther 2018; 21:419-429. [PMID: 28536827 DOI: 10.1007/s40291-017-0279-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The aim of this review was to provide an evidence-based approach to frequently asked questions relating to the risk of transmitting a maternally inherited mitochondrial disorder (MID). We do not address disorders linked with disturbed mitochondrial DNA (mtDNA) maintenance, causing mtDNA depletion or multiple mtDNA deletions, as these are autosomally inherited. The review addresses questions regarding prognosis, recurrence risks and the strategies available to prevent disease transmission. The clinical and genetic complexity of maternally inherited MIDs represent a major challenge for patients, their relatives and health professionals. Since many of the genetic and pathophysiological aspects of MIDs remain unknown, counselling of affected patients and at-risk family members remains difficult. MtDNA mutations are maternally transmitted or, more rarely, they are sporadic, occurring de novo (~25%). Females carrying homoplasmic mtDNA mutations will transmit the mutant species to all of their offspring, who may or may not exhibit a similar phenotype depending on modifying, secondary factors. Females carrying heteroplasmic mtDNA mutations will transmit a variable amount of mutant mtDNA to their offspring, which can result in considerable phenotypic heterogeneity among siblings. The majority of mtDNA rearrangements, such as single large-scale deletions, are sporadic, but there is a small risk of recurrence (~4%) among the offspring of affected women. The range and suitability of reproductive choices for prospective mothers is a complex area of mitochondrial medicine that needs to be managed by experienced healthcare professionals as part of a multidisciplinary team. Genetic counselling is facilitated by the identification of the underlying causative genetic defect. To provide more precise genetic counselling, further research is needed to clarify the secondary factors that account for the variable penetrance and the often marked differential expressivity of pathogenic mtDNA mutations both within and between families.
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Affiliation(s)
- Joanna Poulton
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Oxford, UK
| | - Josef Finsterer
- Krankenanstalt Rudolfstiftung, Postfach 20, 1180, Vienna, Austria.
| | - Patrick Yu-Wai-Man
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.,Newcastle Eye Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK.,NIHR Biomedical Research Centre, Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK.,Department of Clinical Neurosciences, School of Clinical Medicine, University of Cambridge, Cambridge, UK
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11
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Blomberg J, Gottfries CG, Elfaitouri A, Rizwan M, Rosén A. Infection Elicited Autoimmunity and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: An Explanatory Model. Front Immunol 2018; 9:229. [PMID: 29497420 PMCID: PMC5818468 DOI: 10.3389/fimmu.2018.00229] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/26/2018] [Indexed: 12/13/2022] Open
Abstract
Myalgic encephalomyelitis (ME) often also called chronic fatigue syndrome (ME/CFS) is a common, debilitating, disease of unknown origin. Although a subject of controversy and a considerable scientific literature, we think that a solid understanding of ME/CFS pathogenesis is emerging. In this study, we compiled recent findings and placed them in the context of the clinical picture and natural history of the disease. A pattern emerged, giving rise to an explanatory model. ME/CFS often starts after or during an infection. A logical explanation is that the infection initiates an autoreactive process, which affects several functions, including brain and energy metabolism. According to our model for ME/CFS pathogenesis, patients with a genetic predisposition and dysbiosis experience a gradual development of B cell clones prone to autoreactivity. Under normal circumstances these B cell offsprings would have led to tolerance. Subsequent exogenous microbial exposition (triggering) can lead to comorbidities such as fibromyalgia, thyroid disorder, and orthostatic hypotension. A decisive infectious trigger may then lead to immunization against autoantigens involved in aerobic energy production and/or hormone receptors and ion channel proteins, producing postexertional malaise and ME/CFS, affecting both muscle and brain. In principle, cloning and sequencing of immunoglobulin variable domains could reveal the evolution of pathogenic clones. Although evidence consistent with the model accumulated in recent years, there are several missing links in it. Hopefully, the hypothesis generates testable propositions that can augment the understanding of the pathogenesis of ME/CFS.
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Affiliation(s)
- Jonas Blomberg
- Department of Medical Sciences, Uppsala University, Clinical Microbiology, Academic Hospital, Uppsala, Sweden
| | | | - Amal Elfaitouri
- Department of Infectious Disease and Tropical Medicine, Faculty of Public Health, Benghazi University, Benghazi, Libya
| | - Muhammad Rizwan
- Department of Medical Sciences, Uppsala University, Clinical Microbiology, Academic Hospital, Uppsala, Sweden
| | - Anders Rosén
- Department of Clinical and Experimental Medicine, Division of Cell Biology, Linköping University, Linköping, Sweden
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12
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Varma H, Faust PL, Iglesias AD, Lagana SM, Wou K, Hirano M, DiMauro S, Mansukani MM, Hoff KE, Nagy PL, Copeland WC, Naini AB. Whole exome sequencing identifies a homozygous POLG2 missense variant in an infant with fulminant hepatic failure and mitochondrial DNA depletion. Eur J Med Genet 2016; 59:540-5. [PMID: 27592148 DOI: 10.1016/j.ejmg.2016.08.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 08/04/2016] [Accepted: 08/31/2016] [Indexed: 11/26/2022]
Abstract
Mitochondrial DNA (mtDNA) depletion syndrome manifests as diverse early-onset diseases that affect skeletal muscle, brain and liver function. Mutations in several nuclear DNA-encoded genes cause mtDNA depletion. We report on a patient, a 3-month-old boy who presented with hepatic failure, and was found to have severe mtDNA depletion in liver and muscle. Whole-exome sequencing identified a homozygous missense variant (c.544C > T, p.R182W) in the accessory subunit of mitochondrial DNA polymerase gamma (POLG2), which is required for mitochondrial DNA replication. This variant is predicted to disrupt a critical region needed for homodimerization of the POLG2 protein and cause loss of processive DNA synthesis. Both parents were phenotypically normal and heterozygous for this variant. Heterozygous mutations in POLG2 were previously associated with progressive external ophthalmoplegia and mtDNA deletions. This is the first report of a patient with a homozygous mutation in POLG2 and with a clinical presentation of severe hepatic failure and mitochondrial depletion.
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Affiliation(s)
- Hemant Varma
- Department of Pathology and Cell Biology, Columbia University, 630 W, 168th Street, New York, NY 10032, USA; Division of Personalized Genomic Medicine, Department of Pathology and Cell Biology, Columbia University Medical Center, USA
| | - Phyllis L Faust
- Department of Pathology and Cell Biology, Columbia University, 630 W, 168th Street, New York, NY 10032, USA
| | - Alejandro D Iglesias
- Division of Medical Genetics, Columbia University, New York Presbyterian Hospital, USA
| | - Stephen M Lagana
- Department of Pathology and Cell Biology, Columbia University, 630 W, 168th Street, New York, NY 10032, USA
| | - Karen Wou
- Division of Genetics, New York Presbyterian Hospital, USA
| | - Michio Hirano
- Department of Neurology, Columbia University Medical Center, USA
| | | | - Mahesh M Mansukani
- Department of Pathology and Cell Biology, Columbia University, 630 W, 168th Street, New York, NY 10032, USA; Division of Personalized Genomic Medicine, Department of Pathology and Cell Biology, Columbia University Medical Center, USA
| | - Kirsten E Hoff
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA
| | - Peter L Nagy
- Department of Pathology and Cell Biology, Columbia University, 630 W, 168th Street, New York, NY 10032, USA; Division of Personalized Genomic Medicine, Department of Pathology and Cell Biology, Columbia University Medical Center, USA
| | - William C Copeland
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709, USA.
| | - Ali B Naini
- Department of Pathology and Cell Biology, Columbia University, 630 W, 168th Street, New York, NY 10032, USA; Division of Personalized Genomic Medicine, Department of Pathology and Cell Biology, Columbia University Medical Center, USA.
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13
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Finsterer J, Zarrouk-Mahjoub S, Daruich A. The Eye on Mitochondrial Disorders. J Child Neurol 2016; 31:652-62. [PMID: 26275973 DOI: 10.1177/0883073815599263] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 07/08/2015] [Indexed: 11/16/2022]
Abstract
Ophthalmologic manifestations of mitochondrial disorders are frequently neglected or overlooked because they are often not regarded as part of the phenotype. This review aims at summarizing and discussing the etiology, pathogenesis, diagnosis, and treatment of ophthalmologic manifestations of mitochondrial disorders. Review of publications about ophthalmologic involvement in mitochondrial disorders by search of Medline applying appropriate search terms. The eye is frequently affected by syndromic as well as nonsyndromic mitochondrial disorders. Primary and secondary ophthalmologic manifestations can be differentiated. The most frequent ophthalmologic manifestations of mitochondrial disorders include ptosis, progressive external ophthalmoplegia, optic atrophy, retinopathy, and cataract. More rarely occurring are nystagmus and abnormalities of the cornea, ciliary body, intraocular pressure, the choroidea, or the brain secondarily affecting the eyes. It is important to recognize and diagnose ophthalmologic manifestations of mitochondrial disorders as early as possible because most are accessible to symptomatic treatment with partial or complete short-term or long-term beneficial effect. Ophthalmologic manifestations of mitochondrial disorders need to be appropriately diagnosed to initiate the most effective management and guarantee optimal outcome.
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Affiliation(s)
| | | | - Alejandra Daruich
- Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Switzerland
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Kuo ML, Lee MBE, Tang M, den Besten W, Hu S, Sweredoski MJ, Hess S, Chou CM, Changou CA, Su M, Jia W, Su L, Yen Y. PYCR1 and PYCR2 Interact and Collaborate with RRM2B to Protect Cells from Overt Oxidative Stress. Sci Rep 2016; 6:18846. [PMID: 26733354 PMCID: PMC4702135 DOI: 10.1038/srep18846] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/26/2015] [Indexed: 12/20/2022] Open
Abstract
Ribonucleotide reductase small subunit B (RRM2B) is a stress response protein that protects normal human fibroblasts from oxidative stress. However, the underlying mechanism that governs this function is not entirely understood. To identify factors that interact with RRM2B and mediate anti-oxidation function, large-scale purification of human Flag-tagged RRM2B complexes was performed. Pyrroline-5-carboxylate reductase 1 and 2 (PYCR1, PYCR2) were identified by mass spectrometry analysis as components of RRM2B complexes. Silencing of both PYCR1 and PYCR2 by expressing short hairpin RNAs induced defects in cell proliferation, partial fragmentation of the mitochondrial network, and hypersensitivity to oxidative stress in hTERT-immortalized human foreskin fibroblasts (HFF-hTERT). Moderate overexpression of RRM2B, comparable to stress-induced level, protected cells from oxidative stress. Silencing of both PYCR1 and PYCR2 completely abolished anti-oxidation activity of RRM2B, demonstrating a functional collaboration of these metabolic enzymes in response to oxidative stress.
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Affiliation(s)
- Mei-Ling Kuo
- Department of Molecular Pharmacology, Beckman Research Institute at City of Hope, Duarte, CA 91010, USA
| | - Mabel Bin-Er Lee
- Department of Molecular Pharmacology, Beckman Research Institute at City of Hope, Duarte, CA 91010, USA
| | - Michelle Tang
- Department of Molecular Pharmacology, Beckman Research Institute at City of Hope, Duarte, CA 91010, USA
| | - Willem den Besten
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Shuya Hu
- Department of Molecular Pharmacology, Beckman Research Institute at City of Hope, Duarte, CA 91010, USA
| | - Michael J. Sweredoski
- Proteome Exploration Laboratory, Division of Biology and Biological Engineering, Beckman Institute, California Institute of Technology, Pasadena, CA, 91125
| | - Sonja Hess
- Proteome Exploration Laboratory, Division of Biology and Biological Engineering, Beckman Institute, California Institute of Technology, Pasadena, CA, 91125
| | - Chih-Ming Chou
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan 110
| | - Chun A. Changou
- Integrated Laboratory, Center of Translational Medicine, Taipei Medical University, Taipei, Taiwan 110
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan 110
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan 110
| | - Mingming Su
- University of Hawaii Cancer Center, HI 96813, USA
| | - Wei Jia
- University of Hawaii Cancer Center, HI 96813, USA
| | - Leila Su
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan 110
| | - Yun Yen
- Department of Molecular Pharmacology, Beckman Research Institute at City of Hope, Duarte, CA 91010, USA
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan 110
- Integrated Laboratory, Center of Translational Medicine, Taipei Medical University, Taipei, Taiwan 110
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan 110
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan 110
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15
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Ahmed N, Ronchi D, Comi GP. Genes and Pathways Involved in Adult Onset Disorders Featuring Muscle Mitochondrial DNA Instability. Int J Mol Sci 2015; 16:18054-76. [PMID: 26251896 PMCID: PMC4581235 DOI: 10.3390/ijms160818054] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 07/27/2015] [Accepted: 07/28/2015] [Indexed: 12/31/2022] Open
Abstract
Replication and maintenance of mtDNA entirely relies on a set of proteins encoded by the nuclear genome, which include members of the core replicative machinery, proteins involved in the homeostasis of mitochondrial dNTPs pools or deputed to the control of mitochondrial dynamics and morphology. Mutations in their coding genes have been observed in familial and sporadic forms of pediatric and adult-onset clinical phenotypes featuring mtDNA instability. The list of defects involved in these disorders has recently expanded, including mutations in the exo-/endo-nuclease flap-processing proteins MGME1 and DNA2, supporting the notion that an enzymatic DNA repair system actively takes place in mitochondria. The results obtained in the last few years acknowledge the contribution of next-generation sequencing methods in the identification of new disease loci in small groups of patients and even single probands. Although heterogeneous, these genes can be conveniently classified according to the pathway to which they belong. The definition of the molecular and biochemical features of these pathways might be helpful for fundamental knowledge of these disorders, to accelerate genetic diagnosis of patients and the development of rational therapies. In this review, we discuss the molecular findings disclosed in adult patients with muscle pathology hallmarked by mtDNA instability.
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Affiliation(s)
- Naghia Ahmed
- Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, via Francesco Sforza 35, Milan 20122, Italy.
| | - Dario Ronchi
- Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, via Francesco Sforza 35, Milan 20122, Italy.
| | - Giacomo Pietro Comi
- Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Dino Ferrari Centre, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, via Francesco Sforza 35, Milan 20122, Italy.
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16
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Bochman ML. Roles of DNA helicases in the maintenance of genome integrity. Mol Cell Oncol 2014; 1:e963429. [PMID: 27308340 PMCID: PMC4905024 DOI: 10.4161/23723548.2014.963429] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 07/25/2014] [Accepted: 09/01/2014] [Indexed: 11/19/2022]
Abstract
Genome integrity is achieved and maintained by the sum of all of the processes in the cell that ensure the faithful duplication and repair of DNA, as well as its genetic transmission from one cell division to the next. As central players in virtually all of the DNA transactions that occur in vivo, DNA helicases (molecular motors that unwind double-stranded DNA to produce single-stranded substrates) represent a crucial enzyme family that is necessary for genomic stability. Indeed, mutations in many human helicase genes are linked to a variety of diseases with symptoms that can be generally described as genomic instability, such as predispositions to cancers. This review focuses on the roles of both DNA replication helicases and recombination/repair helicases in maintaining genome integrity and provides a brief overview of the diseases related to defects in these enzymes.
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Affiliation(s)
- Matthew L Bochman
- Molecular and Cellular Biochemistry Department; Indiana University ; Bloomington, IN USA
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Nogueira C, Almeida LS, Nesti C, Pezzini I, Videira A, Vilarinho L, Santorelli FM. Syndromes associated with mitochondrial DNA depletion. Ital J Pediatr 2014; 40:34. [PMID: 24708634 PMCID: PMC3985578 DOI: 10.1186/1824-7288-40-34] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 03/28/2014] [Indexed: 01/21/2023] Open
Abstract
Mitochondrial dysfunction accounts for a large group of inherited metabolic disorders most of which are due to a dysfunctional mitochondrial respiratory chain (MRC) and, consequently, deficient energy production. MRC function depends on the coordinated expression of both nuclear (nDNA) and mitochondrial (mtDNA) genomes. Thus, mitochondrial diseases can be caused by genetic defects in either the mitochondrial or the nuclear genome, or in the cross-talk between the two. This impaired cross-talk gives rise to so-called nuclear-mitochondrial intergenomic communication disorders, which result in loss or instability of the mitochondrial genome and, in turn, impaired maintenance of qualitative and quantitative mtDNA integrity. In children, most MRC disorders are associated with nuclear gene defects rather than alterations in the mtDNA itself. The mitochondrial DNA depletion syndromes (MDSs) are a clinically heterogeneous group of disorders with an autosomal recessive pattern of transmission that have onset in infancy or early childhood and are characterized by a reduced number of copies of mtDNA in affected tissues and organs. The MDSs can be divided into least four clinical presentations: hepatocerebral, myopathic, encephalomyopathic and neurogastrointestinal. The focus of this review is to offer an overview of these syndromes, listing the clinical phenotypes, together with their relative frequency, mutational spectrum, and possible insights for improving diagnostic strategies.
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Affiliation(s)
| | | | | | | | | | - Laura Vilarinho
- National Institute of Health, Genetics Department, Research and Development Unit, Porto, Portugal.
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Abstract
BACKGROUND Charles Darwin (CD), "father of modern biology," suffered from multisystem illness from early adulthood. The most disabling manifestation was cyclic vomiting syndrome (CVS). This study aims at finding the possible cause of CVS in CD. METHODS A literature search using the PubMed database was carried out, and CD's complaints, as reported in his personal writings and those of his relatives, friends, colleagues, biographers, were compared with various manifestations of mitochondrial disorders (MIDs), known to cause CVS, described in the literature. RESULTS Organ tissues involved in CD's disease were brain, nerves, muscles, vestibular apparatus, heart, gut, and skin. Cerebral manifestations included episodic headache, visual disturbance, episodic memory loss, periodic paralysis, hysterical crying, panic attacks, and episodes of depression. Manifestations of polyneuropathy included numbness, paresthesias, increased sweating, temperature sensitivity, and arterial hypotension. Muscular manifestations included periods of exhaustion, easy fatigability, myalgia, and muscle twitching. Cardiac manifestations included episodes of palpitations and chest pain. Gastrointestinal manifestations were CVS, dental problems, abnormal seasickness, eructation, belching, and flatulence. Dermatological manifestations included painful lips, dermatitis, eczema, and facial edema. Treatments with beneficial effects to his complaints were rest, relaxation, heat, and hydrotherapy. CONCLUSION CVS in CD was most likely due to a multisystem, nonsyndromic MID. This diagnosis is based upon the multisystem nature of his disease, the fact that CVS is most frequently the manifestation of a MID, the family history, the variable phenotypic expression between affected family members, the fact that symptoms were triggered by stress, and that only few symptoms could not be explained by a MID.
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Affiliation(s)
| | - John Hayman
- Department of pathology, University of Melbourne, Victoria, Australia
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Horan MP, Cooper DN. The emergence of the mitochondrial genome as a partial regulator of nuclear function is providing new insights into the genetic mechanisms underlying age-related complex disease. Hum Genet 2013; 133:435-58. [DOI: 10.1007/s00439-013-1402-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 11/23/2013] [Indexed: 12/17/2022]
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